Method



April 29 1924.

C. E. WUENSCH METHOD OF AND APPARATUS FOR REDUCING POWDERED ORE IS Filed"March 27 1920 2 Sheets-Sheet 1 abbozwu I N In April 29 1924.

- C. E. WUENSCH METHOD OF AND APPARATUS FOR REDUCING P OWDERED ORESFiled March 2'7, 1920 2 Sheets-$heet 2 U NHEU Patented Apr. 29, 192.4.

UNITED STATES CHARLES EBB WUENSCH, OF GOLDEN, COLORADO.

METHOD 01? AND APPARATUS FOB REDUCING POWDERED ORES.

Application filed March 27, 1920. Serial No. 369,267.

To aZZ 107mm it may concern:

lie it l znown that l, (liiiuzcias llrc i i "unused a citizen or theUnited States, residing at Golden in the county of Jefferson. and Stateof Colorado, haw-c invented certain new and useful Improvements inlvlethods of and Apparatus ior Reducing Pmvdcred Ores, of? which thefollowing is a specification, reference being had. to the accompajny' 1gdrawn z s.

TlllS invention, relates to processes and upj flll'fltllfs' for thesmelting and reduction of powdered ores, l particulariy to the treat-.uiont oi. oxidized ores or mixed oxidized and sulphide ores, and thegeneral object of the invention is to l] prove upon, simplify andrerulcr more el'iective the apparatus dis closed, in my pendingapplication for patent tiled in September, 1918, lerial No. 253,581.

One of the important objects my invention is to provide an apparatus andprocess particularly designed for treating the large deposits ofoxidized and mixed oxidized and sulphide c ppcr orcs oil the Southwest,and which can he further utilized for the purpose oi treati complex leadzinc ores (preferahly flotation concentrates) containing small amountsof copper and other metals.

A, further object is to provide a furnace so construe ed that the oremay be sucked throi: 11 the furnace, and ore passing through the Furnaceis first subjected to exidising conditions and then subjected to reducing conditions, and in which the temperat are oi the dischargeportion or the furnace greatly lowered or cooled so that the metallic pacles and the gangue particles dischaz' ed in the Form of dust, and rings] o a inst receiving chamber, the g. s rig withdrawn from this chanilr, and the dust also taken away for concenn ation or "her treatment.

A further object to provide a method and apparatus of uh coal-actor thatinare evolved which may be flannnable gases used for the purpose ofdriving the grind- 1 elevating and suction blower or this character theore in a coarsely crushed form may be dried by pass iug it over that g."on oi the tubular fur nace wherein the temperature is to he reduced,thus utilising he coarsely ground ore tor the pulp oi ducing ti o tcrcrature and at the some time utilizing this heat for the purpose ofpreheating the air, and to dry the ore preparatory to fine crushing.

Another object is to provide a furnace in which the cooling portion ofthe tubular furnace may be utilized not only for the purpose of treatingthe coarsely ground ore but may be utilized for the purpose of roastingrelatively finely ground ore pre vious to its discharge into the furnaceitself for the oxidizing and reducing operations.

Still another object is to provide means for cooling the dischargeportion of the furnace providing a jacket surrounding that portion ofthe furnace supplying air to this jacket and thus preheating the air andat the same time cooling this portion of the furnace and utilizing thisheated air in connection with the burners discoarging oil, powderedcoal, or producer gas into the inlet end of the furnace.

A further general object is to provide a process and apparatus by whichit is possiale to treat oxidized ores of copper occurring in limestonegangue which are not :unenable to leaching processes using acid as asolvent, and further which is capable of treating mixed oxidized andsulphide ores which are not amenable to ammonia or acid leaching becauseof the insolubility of the sulphide particles in the solvent, andfurther whereby a very high-grade concentrate can he produced with aboutthe fuel consumption used in ordinary methods of smelting and with thevery important ad wintage that no iluxing is necessary.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawings, wherein Figure1 is a longitudinal sectional view of a furnace constructed inaccordance with my invention;

Figure 2 is a section on the line 22 of Figure 1;

Figures 3 and 4: are enlarged longitudinal sectional views through thetwo fire boxes;

Figure 5 is a diagrammatic top plan view of the complete plant.

In the accompanying drawings, I have illustrated an embodiment of thepowdered ore smelter used in carrying out my process, and in thesedrawings A designates a flue, which, for the greater portion of itslength is upwardly ext-ending, but which, at its entrance end, isrelatively horizontal, as

at 10. This flue for a certain portion 0 ordinary nricl: i0, and thisbrick portion is lined with a refractory lining ll of chromite. Thisline of fire brick is continued by means of a cast iron section 12, alsoupwardly and iorx'vardly inclined, and terminating in a portion orsection 13 which extends into a dust separator, as will be later stated.The brick 11 tends around the under side of the cast iron section 12, asillustrated in Figure 2, but is spaced therefrom to provide an airp'eheating chamber 1% which has the length of the section 12 and isconnected to a blower and has checlreiwvorl; therein. Pr ferably, thoughnot necessarily, the combustion chamber, oesignated B, which extendsfrom practically the rear end of the furnace to the cast iron extension12, will be "ll-shaped in cross section and have a flat top. Thecastiron section 12 will also be ti-shaped in cross section, andextending across the top of the section 1:? will be a cast iron plate15, to which will be attached angle irons 16 having upwardly extendingflanges, these angle irons extending along the margin of the plate 15.

it its rear end the combustion chamber will have the torn in crosssection illus trated in Figure l to form an oxidizing nre box C, as iwill hereafter call .l ing into this fire box will be a plurality of oilor gas burners, illustrated in detail in Figure 3, each of these burnerscomprising an oil pipe 17 which extends into an air chamber 18, this oilpipe extending out from the air chamber in the form of a nozzle and theair chamber having perto 'ations 19 in its wall concentric to thenozzle, these perforations or air nozzles being so directed as todischarge the air in a cone surrounding the discharging jet 01"" oil(see Figure i). This is an ordinary term of oil burner, and do not wishto be limited to this but have merely described it for illustrativepurposes. The ilaincs discha from these burners will strike a bafiiewall 20 which will deflect the flames slightly npwari'l and "Forward.Forward oi this oxidizing .hre be C formed by the section 10 is astorage bin D having a hopper-shaped bottom discharging or feedingdownward into he top of the combustion. chamber B whereby "very finelypowdered ore may be discharged into the combustion chamber. This storageiced bin D is shown as being provided with a shaker screen feeder 21 atits discharge end, but this shaker screen has been illustrateddiagrammatically, as its construction is common and well known. Fromthis point onward the fine or combustion chamber B extends at a slightuoward inclination, and beyond the point where the powdered ore entersthe comb ,stion chamber a second li e ox ti is formed having an upwardlyand i argino on 1 ane 23 iiitcrsecting tne b ttoni oi: the Cor osstionchamber l T is fire box s a so former b0 this end ha upon the hat top ofthis fine section two coni'eyors whereby ore may be conveyed along thefiat upper surface of the fine section 12 and either dried or roasted.he portion section 12 constit .ihe roast- )ortion oi the fine, and thepoi-tum l section of the line. .l have illusupon each c conveyor mountedor these sections. Each of the come-yors consists of a longitudinalelement having downwardly extending rake bla lcs, the ralte being givena circular movement by eccentrics or other suitable means 25 w willcause the rake to shift the ore over the surface oi the section 12. Theore to be dried is, of course, ished ore delivered to the drying sectionfrom a bin C but in order to roast this ore it must be crushed, and,therefore, the ore delivered from the drier section is taken by aconveyor H to a bin 5 and thence to suitable crushing means, as forinstance, crushing rolls l, and then this timely crushed ore is screenedby screen. and conveyed to the upper end oi the roasting section B andcaused to travel over this roasting section to the feed stor D, as bymeans of the elevator a. ore to be roasted, then the wl 7 tion 12 isused as a drier and ti It is carried to the storage bi; T by a conveyorto the c t. to the shaking screen 7 conveyor (Z to the bin into the siil ii y or ushproducts pass the flue, it pro the burners, it v ore, and,desi crush d ore.

From the mouth 18 of combustion flue or chamber ore udiieh L theparticles or have been treated within the ilICll combustion chamber eredischer 'ed into a. due SQPilftItOl, designated generally N. This dustseparator has n conical, hoppershaped bottom from which a conveyor itleads. The upper end of this dust separator connected by a duct to asuction fan O of any suituhle or usual construction, and which isccnnecled by s pipe 0 to a. stack, and forms a discharge pipe for the:l'urnare gases. From this discharge pipe leads gas hurners l7discharging onto the hoiler Q. which hoiler may he used. for operatingthe steam turbine 01" other Orin engine in turn operating an electricnorutor S from which power may be taken for the purpose of operating theblower Q7, llw slono ln'eaker hi. the of crushing; rolls .T and theseveral elevators and ronvrrs. and operating; the ball mill. :fiass'lirrand concentrators to he described.

ll il hin the dust separator is disposed a spiral. hallle wall 30 whichextends from the wall of the dust separator N to one side of the inoljuh13 of the comlinistion chamber and. which extei'uils around in ugradually decreasing volute for a. certain distance so that the trentcdore discharged into the dust sir-pa *stor will he obliged to travel in acircular path before it can possibly diszharge into lhe body of theseparator N. and so that this ponwlercd ore and the gases travellingwith it will not be sucked out by the suction :lau until the ore hastime to settle 'a the form of dust in this dust separator.

The lower cud of the dust separator disrhaiees i1 .0 the conveyor u, aspreviously stated. and this conveyor it carries the ore to n. storagebin T, from which it he carried hy a. conveyor 15 to it ball. mill U,from which in turn the ore dust which has new li en finely powdered inconveyed to the classifier V. From this classifier the rclutively coursematerial. is charged onto a roncen'hha.ting tahle V ol any suitehle formor cl'iarsurter. from which the middlings are carried hack by e conveyoror trough w to he egain operated on by the ball mill. The lines from theclassifier are curried onto th shine tables X where they areconcentraled, and the niiddline s from these tables are ca ried buck forregriuding to the ball, mill, while the tiilingzs are carried to thewaste (limp.

l t l be understood, as before remarked. concentrating N and X and i 1will. the classifier and he convey- .ry thcreror will. all be operatedmy n taken from the generator S. and

it also to he understood that the illus- "."lTlOH ol the variousconveyors. storage rini'lingg zinc crushing mills, CODCQI1- theclassifier, blowers etc", are conventimial, and that my inventionlimited to t c use oil any @articulur of these various devices or.structiu'esvv sir into the any ecsired n'ieans dered coal or other ficombustion chamber. furnace is as follows 1*- It will h understood, oicourse that th suction fan C exerts contin -.ous drni through thecomlnistion choinhe' B so the the finely powdered ore with envelope oil?gas is drawn through the combustion rhemher from the mouth ol. thestorage feed hin into the dust separator. In that portion of: thecombustion chemoer from the entrance of the storage feed bin to thereducing fire box 22, the ore is oxidized. In that portion of thefurnace from the reducing lire ho}: 22 to the cast iron flue sec tion12, whicl'i, it is emphasized, constitutes o. cooler t is ore isreduced. In the cast iron sections 12 and 1.3, the temperature of the orgreatly reduced hy thecooling action oi the air in the chamber 1.4. andthrough the abstraction oi the heel: by the drying or roasting of theore travelling on the top of the section 152. The sections 12 and 13therefore, constitute a cooler. The temperature in the oxidizing fire hos so proximately 1200 C. The temperatun in the oxidizing portion of thefu nace from the point where the ore is into the combustion chamber tothe point where the reducing finrnes impinge on the column of powderedore is approxirnetely 800 C. This temperature is gradually reduced fromthe point of intersection of the reducing lire hex the point ofconnection to the cooling sr-o' n 12 so that at junction with t coolinsection, the te oeruture with n the comhistion cl'isinher reduce toapproximately 500 0. end ture is former gradually coi'ilcr until the oreand perature of about 260 C. 21 they are discharged into the dustseparator.

It is to be understood that the lire boxes C and C are relatively largeso as not to smother the Home but to secure full combustion before theflerne is brought into contact with the ore. While the size of thefurnace Will necessarily vary with different conditions, yet as oninstance it may he stated tout thntporl'ion ofthe furnace 'oiu theendofthe oxi(lit xiii; fire hot; to Where the fine 23 the combustionchamber will he about 20 long. that portion of the combustion cheznherfrom the reducer; hox the section in the 12 i be al out 40 long, andthat from the hen 1 of section 12 to the end thereof C will be about 75,While that portion of the furnace which I have illustrated as being between the drier and the dust separating chamber hl Will be from 50 to160 long, This portion oi? the turns eel?) is also to be considered apart of the cooler. l have illustrated the section 152 as beingsurrounded or parti ally surrounded by an air jacket in order to preheatthe air which passes to the furnace burners, but it is to be understoodthat other means might be used for cooling this portion of the furnace,and that any means might be 'g'n-ovided this poi ion of the furnace iscooled by means e rior to the furnace as distinguished from thedischarge of Water into this portion of the furnace.

In the peratiou of this mechanism, the dry ore which has been finelycrushed to pass through. a 10 to ll) mesh screen, varying with differentores, is carried to the storage bin D, from which it is disch: rged bymeans ol the shaking screen t'ceder 21 into the combustion chzunber,Where it is immediately surrounded by the ignited enveloping gases ssingfrom the burners into the oxidizing boa: o. in (*ZCPSF? ol air enterswith the gases in the oxidizing lire box so that betvcen its point ofentrance and the entrance of flue 23, the ore is subjected to a temperature of about 80 O and is oxidized. From the point of entrance oi theflu: leading from the reducing lire box, the ore is subjectcd toreducing conditions and thus the metallic oxides in the ore are reducedto a metallic state Whe'eas the gangue metals are una"ected. Themetallic particles and the gangue particles, with the gases, are thendrawn through the cooling p lrtion ot the l' l at is the portions 1 andl, and

(l a i p ting this dust to settle the bottom the parator,"whiiethe gasesare drawn out igh the suction if Q and (ha-t 0, and

are burned. it co r 0. are being recurred to metallic copper, for thepurpose of gene 'ating steam to secure power to opcrate the variouselevators, shakers, grinding mills, etc. The cooler, consisting of thepor tions 12 and 13 out the :turna e, is of great impor ance, as by thismeans the solid l gaseous products are sufiiciently cooled so that the mallic particles will not l e again oxidized to their respective oxideswhen they cone in contact with air in the settling or sernaratorchamber, as would be the case Were the metallic particles at a high to.1- pernture, torzed directly into the settling chamber, and intocontact with air there- .t. from which they are carried to the ball millU, and they are therein Wet ground. This regrinding ot the metallic andgangue particles which are collected from the dust separator it is avery vital feature of my invention for the reason that l have :foi'indby microscopic ei-zamination that the metallic copper which is formed inthe course of the nassage of the ore through the furnace and rhiah is:harged into the dust separator, porous,,so much so that this dust zaton vatcr and that the particles of rust or metallic copper are veryline, though the specific gravity of the copper relatively heavy and itis attempted to concentrate ivi ll ot the erdini'y concentrating tables.It thus be seen that this rcgrinding of the par- "ieles or copper isparticularly necessary to e complete operation of my invention. Byvirtue of tl e conversion of the OXl. dined minerals, as malachite, forexample, With a specific gravity of 3.8 to metallic cop'- per i aspecific gravity of 8.8, it is possible to ellject a high ratio ofconcentration ecovery.

'3 reason for the provision of the ing tire box and of: the reducingfire box in order that between the point Where the c is 13d into thefurnace and it is being u-ted on. by the flames from the reducing irebox, any sulphide present in the ore may asi'cd to tl 1 the formula 11Mi l this ateiial is he tllffFJlr the zone ot iilG second lire boxreducing conditions will prevail, both the natural. oxidized uiiner- (llas the oxidized minerals formed i particles by roasting, Will to themetal in the presence oi that this is poss. may be underto lo vi". gmolecular ilOil 1- ("alorics f): ,Qllt) sense i s 43,3, U

As before stated, reducing conditions will prevail. in that portion ofthe furnace from the reducing fire box to the cooler and under thesecircumstances the carbon of all the substances present has the greatestallinity for the oxygen in the temperature prevailing in the furnace. Itwill, therefore, rob the material of its oxygen and the result is thatthe metal in the oxides will be reduced to metallic copper first. Thenthe iron will be reduced, if any is presented, and if there is still thesame reducing agent present, the sulphur dioxide will be reduced. Itmight be questioned as to whether the metallic particles will not beconverted into the origi nal sulphide form, but by reference to theheats of formation given above, it will be seen that the sulphur willcombine with the calcium and iron before it will with the copper so thatthis reaction is a protector for the iuctz'illic copper. If the furnaceis properly constructed. and the process properly carried out, it ispossible to control the reducing conditions so that just sufficientcarbon wi l be present to reduce the copper to the metal, and the nextstep may be the reduction of the iron oxide.

llt is to be understood that oxidized copper such as copper oxide orcopper carbonate do not require to be roasted prior to their admissionin powdered form into the furnace, but that if mired sulphide andOKlCllZQCl ores are to be treated, the drier, that is the portion of thefurnace in which the gases and ore are cooled, is to be built in twosections, one being used as a drier and the other for roasting thecopper ore.

Beside the reduction of ores in the manner heretofore described, thisfurnace is also adapted to flash roasting preparatory to magneticconcentration and to the thorough )hate roasting of flotationconcentrates lnrparatory to leaching processes. Thus, in the presentelectrolytic zinc process flotation concentrates a re roasted at atemperature of about 600 (l. to pro cut the formation of the insolublezinc fer ite, but no provision made to cool the roasted product and getthe temperature sufliciei'itly lOW to favor sulphating. '1 result is theproduction of a very small portion of the zinc in the form of watersoluble ilphate. With my appais pt ole to suck the flotation con msthrough the fun ace with the ore ,ing conditions prevailing and the tem-"men .00 and 900 (1, to roast s to the oxides or form zinc roastedparticles and the znbnstion S0,, and CO are U gh the cooling portion ofchamber in which the temure will, at some point along the tube, rrectfor instantaneous sulphating. The SC, under these conditions also breaksup hieu drawn t l l the comlmstio.

any insoluble zinc ferrites and converts them into Water soluble zincsulphate.

It will be obvious that With the relatively long, tubular furnace WhichI have described, and with the gradual reduction in temperature from theentrance end of the furnace to the discharge end thereof, that somewherealong this line the temperature will be exactly right for sulphating tooccur, and that the production of this temperature is automatic, that itis inherent in the construction of the furnace and in the manner inWhich it is operated, and in this connection it may be stated that anexcess of gas may be allowed to enter the burners so as to secure thissulphating action.

This furnace and the process above de scribed may also be used for thepurpose of reducing copper silicates, and then the silica separated fromthe copper by crushing the dust collected in the dust collecting chambermay be separated and concentrated by the flotation method. The gas drawnfrom the furnace by the suction fan 0 Will be ordinarily passed througha scrubber before passing to the burners P. I have not illustrated thisscrubber, as the treatment of producer gas is Wel known.

The following points will emphasize in general the advantages of theprocess and also its special applicability: The oxidized copper ores areusually found in arid regions Where water is scarce, and many depositstoo small to Warrant the expenditure necessary to develop sufficientWater for leaching (3 to 6 tons of Water per ton of ore being usuallyrequired) or the heavy expense of a leaching plant. A plant such as hasbeen described will cost approximately $1,000 per ton daily capacity,that is a. 50,000 ton plant will cost about $50,000. Because of the highratio of concentration and high-grade of the concentrates, together withthe low fuel consumption, it is possible by my apparatus to profitablyoperate isolated deposits which are at present valueless. No fluxes arerequired, and it makes no difference Whether the ore is porphyry,limestone or quartz gangue. Mixed oxidized and sulphide ores can betreated in one step, Whereas by leaching methods, as the sulphides areinsoluble in solvent, they require a separate treatment for theirrecoyei'y. The previous metals are in a large part recovered by virtueof their intimate association With the metallic minerals, Whereas whereleaching processes are used, these precious metals being insoluble, require subsequent treatment for their recovcry. T he fuel consumption ofthe furnace very low, being about -1 or of that required in smelting.The furnace is a continuous one. In other Words, there may be acontinuous flow of ore from the storage bin B, which may be filled fromtime to time, however, and a continuous oxidation and reduction of theore in the furnace and its discharge in the form of dust into the dustseparator N, from which the dust may be continuously fed to the grindingmechanism and the concentrators. Thus, no time is lost while theapparatus is closed down for the purpose of cleaning out and putting thefurnace in condition for a new batch of ore. Of course, the storage binsfor the coarsel or .shed ore and the finely crushed ore and the ore tobe delivered to the ball mill U and the crushing mill and theconcentrators could be filled during day shifts so as to keep thefurnace running constantly.

l claim1:

1. An apparatus of the character described including a furnace in theform of a continuous tube, means for discharging finely crushed ore andignited fuel and air into one end of the furnace, means exterior to thefurnace for reducing the tempera ture of the discharge end thereof, anda closed collecting and separating chamber into which the end of thetubular furnace remote from the point of reception of the ore and fuelopens and into which the products from the cooled portion of the furnaceare carried and wherein the solid products are separated from thegaseous products of combustion.

2. An apparatus of the character do scribed including a furnacecomprising a continuous tube, means at one end of the furnace fordischarging fuel, air and crushed ore into the furnace, a separating andcol-- lecting chamber at the opposite end of the furnace into which thedischarge end of the furnace discharges, means for causing a positivesuction through the length of the lurnace from the first named endthrough the collecting and separating chamber, d means for cooling thatportion of the furnace adjacent the separator and collectin chamber.

3. An apparatus of the character described including a tubular furnace,means at one end for discharging fuel and air into the furnace, meansadjacent this end of the furnace for discharging finely crushed orethereinto, a dust collecting and separating chamber at the opposite endof the furnace and into w rich the tubular furnace discharges, meansconnected to the separating and collecting chamber for causing apositire suction through said chamber and through the length of thefurnace to thereb cause all particles to pass into said celled.- ing andseparating chamber, and means for cooling that portion of the furnaceadjacent the separating and collecting chamber.

4t. An apparatus of the character ,c. (all so bad including a tubularfurnace having a practically heat conserving covering for a portion ofits length, means for introducing linel crushed ore, fuel and air intoone end of the covered portion of the furnace, a collector and separatorinto which the other end of the tub in" furnace discharges, and meansconnected to the collector and separa tor for causing a suction throughthe entire length of the furnace, that portion of the furnace notsurrounded by refractory mate-- rial and adjacent to the dust collectorand separator acting to cool the products of combustion. passing throughthis end of the furnace prior to their discharge into the sepa rator andcollector.

5. An apparatus ofthe character described including a tubular furnace, ncans at one end for discharging fuel, air and crushed ore into thefurnace, a separating and collecting chamber into which said furnacedischarges, means connected to the collecting chamber for causing asuction tln'ough the long h. of the furnace and through the collcctingchamber, and in ans for cooling that portion of the furnace adjacent theseparator and collector chamber including an air jacket s rount thispor= on of the nace, ai' nouns for forcing air through said jacket.

6. BS1 apparatus of the character desc ibed including a 11 uilarfurnace, means at one end for discharging fuel, ai and crushed ore intothe furnace, at separating and collecting chamber into which saidfurnace discharges, mcans connected to the collecting chamber forcausing a suction through the length of the furnace and through thecollecting chamber, means for cooling that por tion of the furnaceadjacent the separator and collecting chamber including an air jacketsurrounding this portion of the furnacc, n'ieans for forcing air throughsaid jacket. and means for utilizing the air pro by passage through saidjacket for J. heater.

supporting couibustion within the furnace.

4. an. apparatus ofi'hc character described inc! mg tubular furnacedisposed at an upu'a rd inclination, a sc iiarator and collectingchamber into which the upper end of the furnace discharges, means at thelower end of the llll'llflCO for dischargi :uel and. air into thefurnace, means ad a ent the lower end of the furnace for dischargingfinely crusl'ied ore into the furnace, nunins for cooling that portionof the furnucc adjar-cut the SCplllftll lllg chan'ihcr, and meansconnected to the separ 5mg chamber for causing siution through. thelength of tho "lurna re and scparat :ig chamber. fin paratus or thecharacter describcl including a tubular, upwardly inclined f1 nace, acollecting :uu pa rating chamber into which the l p moaaoe discharges, aburner at the lower end of the furnace discharging fluid hydrocarbontherein and discharging air for combustion thereinto, means in advanceof said burner for discharging crushed ore into the furnace, meansadjacent the separator and collecting chamber for reducing thetemperature of that portion of the furnace, and means connected to theseparator and collecting chamber for causing a suction through theentire length of the furnace and through said collecting and separatingchamber.

9. An apparatus of the character described including a furnacecomprising a relatively straight tube having means adjacent one end fordischarging crushed ore thereinto and having a collecting and separatingchamber at the other end into which the furnace dis charges, meansconnected to said collecting and separating chamber for causing asuction through the length of the furnace and chamber, and means forproducing oxidizing conditions within the furnace.

10. An apparatus of the character described including a tubular furnacehaving means adjacent one end for discharging crushed ore thereinto andhaving a collecting and separating chamber at the other end into whichthe furnace discharges, means con nected to said collecting andseparating chamber for causing a suction through the length of thefurnace and chamber, means for causing an oxidation of the ore discharged into the furnace for a certain period of its travel through thefurnace, means for reducing said ore as it further travels through thefurnace, and means for reducing the temperature in that portion of thefurnace adjacent the separator.

11. An apparatus of the character described including a tubule" furnaceconnected with and discharging into a separator and collecting chamber,burners at the end of the furnace opposite the separating chamberdischarging fluid hydrocarbon and air into the furnace, means fordischarging crushed ore into the furnace in advance of said burir ers, asecond set of burners discharging into the furnace in advance of thefirst set to thereby produce reducing conditions within the furnace,means for reducing the tempera ture of that portion of the furnace adcent the separating and collecting chamber, and means connected to theseparating and collecting chamber for causing a suction from saidchamber and through the length of the furnace.

12. An apparatus of the character described comprising a tubular furnacehaving a refractory heat conserving covering extending from one endpartially along the length of the furnace, a separating and collectingchamber into which the opposite end of the furnace discharges, meansconnected to the separating and collecting chamber for causing a suctionfrom the separating chamher and through the length of the furnace, afire box connected to and forming part of that end of the furnace remotefrom the separating and collecting chamber and having burnersdischarging air and ignited gas thereinto, a second fire box disposed inadvance of the first named lire box and discharging air and ignited gasinto the furnace, means for discharging crushed ore into the furnacebetween the two fire boxes, and means for reducing the temperature ofthat portion of the furnace adjacent the separat ing and collectingchamber.

13. An apparatus of the character described including a tubular furnace,means at one end for discharging fuel and air into the furnace, meansconnected to the other end of the furnace for causing a suction throughthe length thereof, means at the first named end of the furnace fordischarging crushed ore into the furnace, the fun nace for a certainportion of its length ing protected by a refractory coveri for a certainother portion of length being unprotected, and means for causin totravel over the unprotected portion 0 the furnace whereby said may beheated.

14:. An apparatus of the character described including a tubularfurnace, means at one end for discharging fuel and air into the furnace,means connected to the other end of the furnace for causing a suctionthrough the length thereof, means at the first named end of the furnacefor discharging crushed ore into the furnace, the furnace for a certainportion of its length being protected by a refractory covering and for acertain other portion of its length being unprotected, means fordischarging coarsely crushed ore upon a portion of the unprotectedportion and causing said ore to travel therealong, means for finelycrushing said ore after it has been dried by travelli the furnace andfor discharging q, crushed ore again upon an unprotected POT- tion ofthe furnace and causing it to t avel therealong to thereby roast theore, ano means for conveying said roasted and finely crushed ore intosaid furnace.

15. An apparatus of the character de scribed includ ng a tubularfurnace, means at one end fodisc fuel and air into the furnace, meanscoinec ed to the other end of the :l'urnace for causing a suctionthrough the length thereof, means at the first named end of the furnacefor discharging crushed ore into the furnace. the furnace for a certainportion of its length being protected by a refractory covering and forcertain other portion of its length being unprotected, means for causingore to travel over the unprotected portion of the furnace whereby oremay be heated, and an air jacket surrounding a portion of theunprotected if g 54 of the l'urnace, said air jacket being connected tothe air inlets of the burners,

and means for forcing air through said jacket and to said burners.

16. An apparatus of the character de scribed including a combustionchamber having means at one end for admit-ting air and means at this endfor discharging crushed ore and earl onaceous material into thecombustion chamber. means for highly heating the combustion chamber fora portion of its length, means for reducing the temperature in thecombustion chamber for the remainder of its length, means for drawingthe particles or". crushed ore and carbon through the combustionchamber, said means including a suction fan connected to the combustionchamber, and a separating and collecting chamber into Which thecombustion chamber discharges and to which the suction tan is connected.

17. A. method oi reducing ores which conin causing a current of finelyground ore to flow through a highly heated combustion chamber in thepresence of air and carbon to thereby cause the oxidatiim and subsequentreduction of the ore, carrying the products in a current through cooler,discharging the products into a collecting chamber and Withdrawing thegases from said chamber.

18. A method of reducing ores which consists in causing a current offinely crushed ore to pass through a highly heated combustion chamber tothereby cause the oxidation and subsequent reduction of the ore, coolingthe reduced particles Without contact: With the outside air, causing thecooled particles to settle in the form of dust. and withdraw ing thecombustion gases from said particles.

19. A method of reducing ores which consists in drawing air andcarbonaceous :lucl and finely crushed ore through a highly heatedchamber to thereby submit the mi);- ture to a temperature sufiicien' yhigh that only those minerals which are reduceal ile by the carbon at apredetermined temperature are acted upon and the other mineralstom)erature of said mixture "s is carthri'iugh the chamber. dischargingthe roducts into a settling and separat nber, and Withdrawing the p articles.

from the inlet torthc cooled for a portion of its u said n o 1 LCLG intoa settling and so "aiing' chamber, and Witl the gases 'l i'tl-lli saidchamber.

21. A. method of reducing ores which con sists in causin a constantcurrent of air to pass through a relatively elongated conibustionchamber and discharging into one end of said chamber ignited fuel, air aore to thereby cause the oxidation. and subsequent reduction of the ore,enteriorly cooling that portion of the chamber remote from the entranceend thereof to thereby reduce the temperature of the products, anddischaruing said products into a separating chamber to thereby permitthe solid particles to settle in the chamber, and Withdrawing the gasestherefrom.

22. A method of reducing ores which consists in admitting ignited :tueland air to one end of a relatively elongated combustion chamber, causinga continuous low of the air and fuel through said chamber :trom one endto the other, cooling that portion of the chamber remote from itsentrance end, con tinuously lischarging linely crushed ore into theentrance end of the chamber, continuously discharging cooled products iro outlet end of the chamber into a settling chamber, permitting the particles to settle into the lower portion of. the chamber and continuouslyWithdrawing the gases from the upper portion of the chamber and thesolid particles from the lower portion of the settling chamber.

23. A method of reducing ore which consists inmizing finely crushed oreand carbonaceous material, the carbonaceous material having suchproportion to the ore a. to cause it to reduce the oxides of the metalspresent in the ore at a pr-edctern'iined temperature, carrying the miXed ore and carbonaceous material through a chamber heated to atemperature sulnciently high that only those minerals that arerei'luceablo by the carbonaceous material. at if e predeterminedtemperature are acted upon and the other minerals in the ore areuna'ilected, cooling the highly heated particles and he products ofcombustion while "he particles are in a finely divided state withoutitllUW- ing the particles to come in contact with air anl thenseparating the cooled iiarticlcs from the gaseous products oicombustion.

554;. A method, oi" reducing ores \Vl'llCll conslots in causing amirrent oi ignited fluid hydrocarbon and air to pass through elongatedcombustion chamber. discharging finely erned ore into the combustioncham- "eby cause the carbon present in e "uel to chemically combine"with the 07-:- metals contained in the ore, exteriortl portion. of thecombustion from th ce end lid ber, utilizing the heat given off from thecombustion chamber at this point as the means for preheating the airentering the chamber, conducting the products into a separating andcollecting chamber and allowing the solid particles to descend to thelower portion of said chamber and removing the gases from the upperportion thereof.

25. A method of reducing ores which con sists in causing a current ofignited fluid hydrocarbon and air to pass through an elongatedcombustion chamber. discharging iinely crushed ore into the combustionchanr her to thereby cause the carbon present in the luel tocommercially combine with the oxides of metals contained in the ore.c2;- teriorly cooling that portion of the combustion chamber remote fromthe entrance end to thereby reduce the temperature of the productspassing through the combustion chamber, utilising said gases for thepurpose oi. generating power conducting the prod ucts into a separatingand collecting cham ber andv allowing the solid particles to descend tothe lower portion of said chamber and removing the gases from the upperportion thereof.

26. A method of reducing ores which con sists in causing a current otignited fluid hydrocarbon and air to pass through an elongatedcombustion chamber. discharging finely crushed ore into the combustionchamher to thereby cause the carbon present in the fuel to chemicallycombine with the oxides of metals contained in the ore. cXteriorlycooling that portion of the combust-ion chamber remote from the entranceend to thereby reduce the temperature of the products passing throughthe combustion chamber. abstracting the heat from the cooling portion ofthe combustion chamber by passing ore thereover and conducting the oreinto the entrance end oi? the furnace. conducting the products into aseparating and collecting chamber and allowingthe solid particles todescend. to the lower portion of said chamber and removing the gasesfrom the upper portion thereof.

27. A method. or": reducing ores which oonsists in causing a current ofignited fluid hydrocarbon and air to pass through an elongatedcombustion chamber, discharging finely crushed ore into the combustionchamber to thereby cause the carbon present in the fuel to commerciallycombine with the oxides or metals contained in the ore, exteriorlycooling that portion of the co1nbus tion chamber remote from theentrance end to thereby reduce the temperature of the products passingthrough the combustion chamber. abstracting the heat from the coolingportion of the furnace by passing coarsely crushed ore thereover to dryit, finely grinding said dried ore and returning it to the coolingportion of the furnace andv passing it. therealong to thereby roast thefinely crushed ore. and then discharging said finely crushed ore intothe entrance end of the furnace, conducting the products into aseparating and collecting chamber and allowing the solid particles todescend to the lower portion of said chamber and removing the gases fromthe upper portion thereof.

2-8. A method of reducing ores which consists in causing the dischargeof ignited fuel and air into one end of an elongated combustion chamber.causing a current of; air and fuel to pass longitudinally through saidchamber from one end to the other. dis" charging finely crushed ore intosaid chamher in advance of the ignited fuel to thereby oxidize the oredischarging ignited fuel and air into the chamber in advance of thepoint of initial entrance of the ore to there by cause the reduction ofthe ore, cooling that portion of the combustion chamber remote from itsentrance end to thereby gradually reduce the temperature of the productswithin the furnace. discharging said products into a collecting andseparating chamber to permit the solid particles to "tall to the bottomof the chamber. and continuously withdrawing the gases from the upperportion of the chamber and the re duced particles from the lower portionof the chamber.

29. A method of reducing ores which consists in causing a current offinely ground ore to flow through a highly heated combustion chamber inthe presence of air and carbon to thereby cause the oxidation andreduction of ore. carrying the products in a current through a cooler.discharging the products into a collectingchamber d with- (lrmring thegases from said chamber. and grinding said solid products taken from thecollecting" chamber to thereby break up the heretofore porous particlesto permit their concentration.

30. A method of reducing ore which con sists in drawing a current-ofignited hydrocarbon fuel. air and finely crushed ore through acombustion chamber to thereby cause the oxidation and reduction of theore. cooling one portion of the combustion chamber to thereby cool thereduced particles without contact with the outside air, causing thecooled particles to settle in the form of dust. and withdrawing thecombustion gases from said particles, and grinding the solid product tothereby break up the heretofore porous particles to make them amenableto concentration.

31. A method of reducing eyes which consists in pemiit-ting ignited fueland air at one end of a relatively elongated combustion chamber. causinga continuous flow of the ore and fuel through said chamber from one endto the otherpcooling that portion of the chamber remote trom itsentrance end, continuously discharging finely crushed ore into theentrance end of the chamber, continuously discharging cooled productsfrom the outlet end of the chamber into a settling chamber, permittingthe solid material to settle in the lower portion of the chamber in theform of dust and continu ously Withdrawing the gases from the up 10 perportion of the chamber, continuously it now 1 41953 005,

withdrawing the solid particles from the lower portion of the settlingchamber, grinding the solid particles to thereby break up the heretoforeporous particles to make them amenable to concentratiom and thenconcentrating said material.

In testimony whereof 1 hereunto aflix my signature.

